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Addressing the challenges associated with census mapping in Africa
Hennie LOOTS
Director, GeoSpace International, South Africa
Abstract
The role of maps in a census is to provide the cartographic basis for enumeration and the platform for spatial census data products such as census atlases. This paper focuses mainly on mapping solutions for enumeration. The paper assesses the traditional methods of census mapping in African countries and aims to provide modern alternatives to the traditional methods that are realistic and achievable given the unique circumstances of the African continent. The paper is therefore of a practical rather than an academic nature. The author strives to provide hands-on and practical solutions based on experience gained in several countries over the last decade. The paper could therefore be of potential use to readers that are responsible for the planning and implementation of the 2010 round of population and housing censuses.
1. Introduction and problem statement
The aim of a population and housing census is to collect, process and publish data on every individual within a defined geographical area usually a country. The aim of census mapping is to provide the cartographic basis to be used during the actual process of counting. The census cartographer therefore needs to provide the census enumeration team with a set of unique maps covering the entire country that accurately defines the boundaries within which each interviewer (enumerator) has to work during the enumeration phase of the census.
In order to do this the census cartographer needs to have access to current maps of sufficient levels of scale and detail. In most African countries the required maps are either very old (often 30 years and older) or in some cases do not exist at all.
Furthermore the census cartographer usually relies on a very small permanent staff and a huge temporary workforce, funded directly from the census budget, to execute the census mapping plan. This is due to the fact that most statistical agencies in Africa are understaffed in general and seriously understaffed in terms of cartographers. It can therefore be stated that the capacity within statistical agencies in Africa to do census mapping is in most cases limited.
2. Conventional mapping
With the above being the status quo in most statistical agencies in Africa the mapping solutions in the past tended to focus on arriving at solutions within the existing framework rather than transforming the existing framework as part of the solution. Given the circumstances and the constraints that faced census cartographers most countries over the years adopted an approach of throwing extensive human resources at the problem once funding for the census become available. This approach implied that huge numbers of people (often referred to as field mappers) were deployed in the field to sketch enumeration area maps whilst sweeping the larger administrative area. The rationale behind this approach was to solve the lack of proper base maps by updating the maps in the field or by creating entirely new maps in the field. During the 2000 round of censuses this methodology was refined with the introduction of Global Positioning System (GPS) technology. GPS contributed to the increase of the absolute accuracy of map updates and sketch maps. The conventional approach provided and today still provides a workable solution in most African countries.
3. Why the need for change?
It can perhaps be argued that it is not necessary to revisit the conventional methods since it provided workable solutions in the past. There are however many reasons why there is a need for change:
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